Electric switch



July 9, 1929. F, J, BAST 1.719.959

ELECTRIC SWITCH yFiled March 1l, 1927 2 Sheets-Sheet 2 d TTHNEYS Puentes July 9, 1929.

UNITED STATES PATENT oFFlcE. t,

FRANK T. BAST, OF BROOKLYN, NEW- IIG. CO., vOIE' BROOKLYN, NEW

YORK, ASSIGNOR TO CHARLES'J. TAGI/IABUE PYOBK, CORPORATION F NEW YORK.

ELECTRIC SWITCH.

. Application led Haren 11, 1927. Serial No. 174,436.

lustrate an example of the invention without- Fig. 1 is a plan view of the,

defining its limits, novel switch; Fig. 2 is a sectional elevation on the line 2-2 of Fi 1; Fig. 3 is a cross section on the line 3-3 o Fig. 2; Fig. lis a simllar view on the line 4.- -4 of Fig. 2.; Fig. 5 is ,an in- 'verted plan view, and Fig.' 6 is a detall perspective view of one of the 'elements of the switch. fr*

As shown inthe illustrated example, the

switch includes abase or support 10 of suitable material and dimensions, and provided` with contact studs 11 or the like forming part of the electrical circuits for `which th'eswitch is designed. If the material, of which the base 10 is made, is a conductor ofelectricity, the contact studs 11 are insulated therefrom and from each other by means of any conventional insulating material 12 as shown in Figs.

land 2.V A switch 1ever'13 is pivotedl at 14 upon a bracket 15 fixed upon the base 10 as by riveting and carries contact members 16 arf' ranged for cooperation with the contact studs 11 to control the opening and closing' of the electrical circuits in which said studs are included. In the preferred form the lever 13 is made in two sections, one of whi ch',"that is'the section 17, is made in suitablez form of any customary insulating material and is 'secured in place to form a rlgid part of the lever 13 in p any convenient manneras by means of lugs 18 comprising integral parts of the lever 13 and bent over the section 17 as Slulownin Figs.

1 and 2. In order toA provide a construction of maximum elliciency which atthe 'same time will accommodate itself to varying degrees of movement ofthe lever 13 with respect to the studs 11, it is preferred to mount the contact members 16 in a resilient-manner upon the section 17 of the lever 13." For this purpose the contact members 16, in the illust:- ated example, are pivotally connected with the section 17 for `instance by being provided at one end with lugs 19 projecting into apertures 20 of the section 17 as shown in Figs. 1 and 2. Springs 21 serve to yieldingly press the members 16 toward and t0 maintain them in surface engagement with' the section 17, said sprlngs belng mounted `upon pins 22 extendmg through; openings in said members 16 and carrled by the section17, the heads'22a of said pins forming abutments for the springs 21 at onel of their ends as illustrated in Fig. 2. A

spring'23 bears withv its one end against the bracket 15 andwith its other end against the lever 13 and in the illustrated example serves to' normally maintain the latter in a position 1n which the contact members 16 arev out ofen- 'gagement with the contact studs 11 or their equivalent as illustrated in Fig. 2. The lever 13 carries a stop which preferably is adjustable thereonand in the illustratedY example is shown in the form ,of a screw 24 mounted in a Aboss 25 and locked in place by means of a locknut 26, said vscrew, having its lower endpointed or otherwise shaped to lit into the recessed end of a stem 27 which passes loosely through an openingirr the base 10. The lower end of thislsteni27 preferably is provided with headv 287 whichnrests against the controlling device which is responsible for the development of the sudden andabrupt movements necessary forconnecting and disconnecting the contact members 16 with and from the contact studs 11 or their equivalent. The controlling' device, in the illustrated example,

comprises a hollow member 29 of any suitable sha e but preferably circular -in form and` having its one wall 30 in the nature of a metal disk possessing the inherent properties necessary to produce the results hereinafter set forth. The member 29 may be fixed in place upon thev su port 10 in any convenient manner and pre erably so as to be removable at will, the 'illustrated example showing a retaining ring 31 for this purpose. The ring 31 engages an annular Harige 32 with which the member 29 in such case is provided and camps it against the` lower face of the support 10, the ring 31 itself bein detachn ably secured in place by means cfg or their equivalent vas shown in Figs. 2, 3 and 5; if necessary or desirable insulation 31a bolts 33 vsure in a l l of such type or of usuch dimensions as not to interfere with the'clamping functions of .the ring 31, may be located between the latter and thesupport 10 as shown in Figs. 2 and 3. The disk 30 is of dished form and at an intermediate point hammered, stretched or otherwise treated and lia'rdened'to provide an active section which, after being developed, possesses the inherent tendency of abruptly snapping from its normal concave position to an opposed concave position upon the application to the inner surface of said disk of pres` redetermined manner. That is to say,the'p ysical'characteristics of the disk 30 are such that thevactive section, without any substantial preliminary movement, will snap into a concave position opposite to that in which it is normally located if suflicient pressure is exerted upon the convex surface of said section, the latter automatically and instantly retbrning to its initial position as soon as the aforesaid pressure is relieved; in'

other words the major movement of the active section in either direction is in the sna so that it is not necessary to lirst adj ust the 'sk, in preliminary adual movements, to a cenl traldposition be ore the snapping movements are eveloped. The pressure whereby the de'- scribed movement of the active section of the disk 30 is effected ma be. developed in any suitable mannerand ymeans of any convenient instrumentalities adapted to automatically actuate the particular switch. For instance as shown in the drawings the interior of the member 29 may be connected by means of an armoredfor other capillary tube 34, which leads'to a thermodynamic bulb of any conventional type, the member 29, tube 34 and bulb in such case being wholly or partly filled with a: luidwhich exerts various pressures in response to variations in temperature externally effective upon the aforesaid thermodynamic bulb.

In any case as pressure in the member 29 is heating the fluid in .the bulb, this pressure will Vbe effective upon the inner surface of the disk 30 and as soon as said pressure .reaches a predetermined point the active 'section of the `disk 30 will be pressed outwardly and almost instantly will snap into a concave osition opposite to that normally occupied y said section at this stage, the disk 30 or the active section thereof, instead of bul 'ng inwardly accordingly bulges outwar y with v respect to the member 29 or its equivalent. As

soon as the pressure is reduced 'or released to a predetermined extent in said member 29, the disk 3Q because of its inherent characteristics immediately snaps back to its initial position cause atmospheric pressure acts thereon. The above snapping action of the disk, in which the major portions of its operative movementspare in the snap, is in contradistinction to a. device in wbichthe active'element is first required to be adjusted in gradual move'- is brought about abruptly and suddenldy. rawvWith the arrangement shown in the ings the pressure in the member 29 whereby l the disk 30 is caused to snap outwardly is developed as a result of increased temperature at the bulb to which the capillary tube 34 leads so that the aforesaid operations of the,

disk 30 are brought about by variations inthe temperature which is externally effective upon said bulb.` The movements of the disk 30 as ressure is applied thereto and removed there? clear from the above description. As the disk section 30 'snaps from its normal position to an opposed position, by the action of pressure developed as explained above, the stem'27 or its equivalent will be'correspondingly forced outward, and by acting upon the stop or screv's1 24 will swin the lever 13 and its associated parts upon te pivot 14 and force the contact members 16 into engagement with the contact studs 11 and thereby close the-electric circuit of which said contact studs form a part; the circuit may include'an alarm or vany device capable of being electrically actuated for a predetermined vpurpose when' the circuit is closed. If the pivotal movement of the lever 13 induced by the action of the disk 30 continues after the contact members 16 have come into engagement with the contact studs 11, the springs 21 will be compressed and'thereby rom are abruptcand'sudden as will be permit excessive independent movement of said lever 13 without injury tothe contact members 16 and without subjecting the saine to undue strain. As soon as thegpre'ssure in `the member 29 drops, as a result of a prede l termined decrease in temperature at thebulb, the disk 30, because of its inherent character\` istics, will at oncel snap back to lits initial po- `sition in a directionaway from the stem 27. By the action of the spring 23 ilpon the lever. 13 the screw 24 will exert al pressure upon the V stem 27 to cause' the latter to follow the re. turn movement of the disk 30, and at thesame time will pivota'lly swing the lever 13 and its associated elements in the reverse direction to s disengage the contact members 16 fromthe contact studs 11 and thereby break the elec-` tric circuits; The operative movements'of the disk-30 being abrupt and sudden over a large fraction of the total movement, the engagepr 'f ment of the contact'fmembers 16 withfald;

their disengagement `froml the contact studs 1l will be vcorrespondingly sudden `and 'i v l' abrupt, so thatarcing and burning of the con- `tact members and contact studs lsj'positively avoided. It will be obvious that-the arrangement may be such that the electrical circuit is broken when the .diskl 30 is bulged from its normal position by the vapplication of pressnapping,

mal concave position to an opposed concave position, to be controlled, a suitable setting or adjusting means is provided. Through this adjusting means, the range of tempera- Vtures may be varied While maintaining the temperature differential substantially constant. As shown in the drawings this means consists of a pressure member preferably circular in form and provided with an annular iiange 35a in engagement with the disk 30 approximately in registry with the peripheral boundary of the'active section thereof as shown in Figs. 2 and 3. Thepressure member 35 includes an axial opening through which the stem 27 passes, and further is provided with recesses f r the'reception ofthe tapering ends of lugs 36 rigidly carried by and projecting from a pressure lever 37; in

addition a positioning pin n 3.8 may project upwardly from the member 35 and through a suitable opening in the support 10 and into an aperture formed in the lever 37 .v The latter is pivotally mounted upon a headed stud 39 fixed upon and projecting perpendicularly p from the base 10 and at its free end is provided with an opening 40 through which a rod 41 fixed upon the base 10 extends as shown in Fig. 2. The up er end ortion of said rod 41 is screw-threaded for t e accommodation of an adjusting or setting nut 42 which constitutes an abutment for one end of a spring 43 mounted upon the rod 41, the other end of said spring 43 engaging the lever 37 near the free end thereof, "and preferably is seated in a recess 44 formed in said lever. Y' L Withl this-arrangementthe spring 43 exerts a resilient pressure upon the pressure llever 37 and thereby, through the medium of the lugs l36 transmits such-pressure to the pressure member 35 to develop a resistance to the snapping of the disk 30 induced by the application of pressure thereto as hereinbefore described. The degree of resistance interposed by the member 35 to the aforesaid may be varied by adjusting the nut 42 upon the rod 41 andthereby changin the tension of the lspring 43 upon the Alever 3` In addition to the parts so far described the device, includes means for changing the differential o f the snapping pressures.V In the illustrated example this means comprises an-annular-member 45 surrounding the presand pivotallysure member 35 and loosely mounted upon the base 10 for instance by means of a pin 46. At a point diametrically opposite to the pivot pin 46, the member 45 is provided with a recess for the reception of the end ofan adjusting screw 47 screwthreaded in the base 10 and secured in an ad@ justed position by means of alock-nut 48 as shown in Fig. 2. The annular 'member 45 is made of such thickness as to permit the disk 30 to assume its maximum convex f orm in an outward direction and to form a posivtive stop against which the rvcdpvexed disk abuts and which prevents any outward bulging thereof beyond this point.

In the'illustrated example of the device a differential exists between the outward snapping-pressureo'f the disk 30 andits inward or return snapping pressure; this differenwill snap inwardly at 25 F. thereby making the aforesaid Vdifferential less.

By operating screw 47 and nut 42 so as to vary the pressure of the annular member 45and the pressuremember 35-on the diaphragm or disk 30, the differential can be changed without changing the mean temerature. For example, if the parts are so adjusted that the disk will snap outwardly at 30 F. and inwardly at 20 F., giving a mean temperature gf 25 F., the nut 42 can be turned so as to 'increase the compression. so that the disc will snap out-` F., while the screw 47 can be in spring 43 wardly at 35 turned so as tocause the member 45to move away from the disk so that the latter will snap inwardly at 15 F., so that the mean temperature of 25 F. will be maintained.

In its finished form the switch is preferably provided wth a cover- 49 .of suitable form detachably securedvinv place upon the support 10 b'y means of screwsor the like 50 an apertured cover 51 being likewise d stubs 11, by means of a screw 52 as' shown by dotted lines in Fig. 2. The device provides an automatically operated electric switch of extreme simplicity an maximum eiliciency in which abrupt and 1nstantaneous operative movements are devel- `oped as a result make and break theelectric circuits in which -the switch is included.

fastene l in place over the binding ends of the contact` The operative movements ofthe device I adapt it specially for making and breaking electric circuits 1n which the current is of a voltage such as is commonly found iii 1light and ower circuits and do away with the possibility of arcing and injury to the contacts and avoid the necessity for'the use of relays I sure; and to snap'back w or e uivale'nt devices to carry the electric load. T e active device whereb these results are obtained comprises generally a metal plate or member ofsingle thickness buckled atan intermediate point by being formed with at least two curvatures to provide an active section which, when subjectedto a suitable pressure applied in .a direction opposite to the normal buckle of the disk or member, will without any material initial movement, suddenly and abruptly snap to an o posed concave -position and which, upon t e relief of such pressure, will abruptly snap back to its initial /srition because of its inherent characteristms. The metal membermay be made of such thicknessand shape as to snap in the indicated manner at any predetermined presen such pressure is reduced. As set forth hereinbefore the range of utility of the switch may be increased'by including therein adjusting means whereby the snapping instants and consequently both Athe tem erature range and differential may be varied 'at will. I

When the pressure whereby the device is controlled, is created as a result of tempera ture variations the gaseous fluid or vo atile liquid upon whlch the temperature is effective may be contained directly-and alone 1n the member 29 or its equivalent, in whlch case the capillary tubing of the illustrated examples and the cooperating thermostatic bulb may be omitted. l

Various changes in the. s ecilic forms shown and described may be ma e within the sco e of the claims without departing from `e spirit of the invention.

I claim:

1. In an electric switch, the combination of a support, contacts carried thereby and forming part of an electric circuit, a switch lever pivotally mounted onsaid support for cooperationwithfsaid contacts to make and break said electric circuit, and a hollow member mounted upon said support and constituting a pressure chamber, one wall of said-member, upon the development of a predetermined degree of pressure in s aid chamber, being adapted tofdevelo snapping movements whereby said switch lever is abruptly actuated relatively to said contacts, apressure member engaging. said snapping wall, a pressure lever o eratively connected with a spring bearing upon said ressure lever, and a setting nut constitutmg an abutment for saidI sprm and arranged to vary the tension thereo on said pressure lever whereby the pressure of said pressure member upon said snapping wall is varied to selectively adjust the snapping instant thereof. f

l I 2. In an electric switch, the combination of a support, a contact carried thereby and forming part of an electric circuit, a. switch lever pivotally mounted in association with said mined degree of pressure in said chamber4 being adapted to develo snapping movements whereby said switc lever is vabruptly actuated relatively to said contact, a pressure member engaging said ysnapping wall, a pressure lever operatively connected with said pressure member, a spring bearing upon said pressure lever, and a setting nut constituting an abutment for said spring and arranged to vary the tension thereof on said pressure lever whereby the pressure of said pressure member upon said snapping wall is varied to selectivelyl adust thesnapping instant thereof.

of a support, contacts carried thereby and forming part of anl electric circuit, switching means cooperating with said contactsto make and break said electric circuit, a. snapping diaphragm located in operative relation to said switching means, said diaphra m upon the application of a predetermined degree of -pressure lbeing adapted to develop a snappin movement which is communicated to n an electric switch, the combination,

sai switching means, an adjustable pressure member bearing upon said diaphragm to vary the snapping pressure thereof, and an adjustable pressure element adapted to bear upon said diaphragm for limiting the snappin movement thereof, whereby the upper` an lower snapping'pressure Ilimits may be ad justed.

4. In an electric switch, the combination of a support, contacts carried thereby and forming part of an electric circuit, switching means cooperating with said contacts to make and break said electric circuit, al snapping diaphragm having an active snap ing portion located inoperative relation to sald switching means, said dia hragm, upon the application of a 'predetermlned degree vof pressure being adapted to; develop a snappin movement which is communicated to sai switching means, and an adjustable pressure element bearing upon saidv diaphragm4 substantially at the perlphery of the active portion thereof to vary the snapping pressure thereof.l

5. In an electric'switch, the combination of a support, contacts carried thereby and forming part of an`electric circuit, switching means coo rating with said contacts to make and brea said electric circuit, a'snapping diaphragm having an active snapping portion located in operative relation to said switching means, sald diaphragm, upon the application of a predetermined degree of pressure being adapted to develop a snapping thereoi` to vary movement which 4is communieated to said switching means, an' adjustable pressure element bearing upon said diaphragm substantially at the periphery of the active portion the snapping pressure thereof, and an .adjustable element in the path 'of movement. of said active portion adjacent the periphery thereof of the pressure for varying the magnitude drop requisite to eiect the return snapping movement.,

In testimony 'W my hand.

hereof I have hereunto set FRANK .L BAsT. 

